Retail sales growth has slowed sharply in recent weeks following a strong September, according to a business survey.

The latest snapshot of sales in the UK from the CBI undershot retailers’ expectations and follows a series of indicators pointing to the UK economy losing momentum. Official figures this week showed UK GDP growth eased in the third quarter.

The CBI’s indicator of retail sales volumes signalled the slowest growth for six months in October. Its survey of 112 firms, which assesses the sector based on a balance of companies’ responses, showed 38% said volumes were up on a year ago, and 20% said they were down. That gave a balance of +19%, compared with +49% in September. Retailers had expected a reading of +51%.

But sales were regarded as above average for the time of year and growth was expected to improve next month. Growth in orders placed upon suppliers was also lower than expected but remained above its long-run average.

Internet sales volumes accelerated in the year to October, with growth set to pick up further next month, the CBI said. The business group said low inflation and improving wages meant the prospects for sales growth were “decent”, but there were still challenges including the weakening global economy and price competition between retailers.

“Growth in sales and orders for high street retailers remains resilient, but there has been a slight slowdown in the pace of that growth following a strong September,” said Rain Newton-Smith, CBI director of economics. “Internet sales are starting to ramp up again as we head towards Christmas and we would expect them to continue this positive pattern until the end of the year.”